The long term research objective (s) of the applicant is that of exploring how alterations in phospholipid metabolism may lead to, or be involved in, the development of pathological processes of the liver, pancreas, kidney and the cardiovascular system. Phospholipids are a major and important constituent of serum lipoproteins and of cellular membranes (structural lipoproteins). Alterations in their synthesis and/or metabolsim can be expected to be reflected in functional lesions of both soluble and structural lipoproteins, leading to pathological manifestations. Some evidence of this has indeed been already obtained by means of two experimental models in animals. In choline-deficient rats quantitative and qualitative changes in the synthesis of lecithins lead to a failure in the conjugation of the various moieties of plasma lipoproteins, and therefrom, to the onset of a fatty liver. Alterations in the functional properties of microsomal and/or plasma membranes of liver cells were also implied by the finding of a delayed release into plasma of proteins (albumin) other than lipoproteins. These findings raise the possibility that alterations in cell membranes may be involved in the development also of the renal an cardiovascular lesions known to occur in choline deficient rats. In preliminary experiments, it has been found also that feeding 2- dimethylethanolamine to mice, leads to the acute onset of an herorrhagic pancreatitis with fat necrosis, and death of the animals.